It's actually both and equally so. I became a customer of Macromedia back in 1999 with Dreamweaver and Fireworks for HTML, CSS, PHP and a bit of ASP. I never really cared for Flash at that time and it would sometimes annoy me a great deal, however that is a long time ago and progress have been made that revolutionized our work and the application we deliver, unfortunately we can't beat Steve Jobs in the media so we are going to kick his ass on the market instead because that we can do and that we will win.
It's not until Macromedia released Flash Communication Server around 2002 that it picked my attention, because that day I was able to build a fully working live audio and video chat with awesome video quality and a very low latency (I could talk on the phone and the delay between the phone and the video was barely noticeable), hosted on my own server with full control and delivered instantly right into the browser, instantly and alway the same on all operating system and browsers combined. to put in context, we are talking about building a live A/V chat chat from scratch, server to client and back, completed in less than a day almost a decade ago. What was W3C doing then? not much as usual, too busy talking and arguing for years over a freaking text file specification called XML.
Even then I was not taking Flash seriously until Macromedia released Flex Presentation Server 1.5 in 2004, that revolutionized web user experience like never before and has remained unmatched ever since. I only started to develop with Flex for a living right after the release of ActionScript 3.0 in 2005, that was a major milestones as ActionScript became a full object oriented programming allowing developers to build large and complex, mission critical applications that look, feel and perform as good as dektop softwares but directly in the browser, instantly with no extra download, install or step.
Prior to that, ActionScript was as good as Javascript is today especially considering that AS1 was straight Javascript with a few custom tags. Now, look what the Flash Platform and ActionScript has become, then turn around and look at the good old same Javascript trying what it can.